Х^2+xy=2 x(x-y)=2 x^2+3x^2+7x-2=0 y-3x=7 y=3x+7 y=3x+7 x^2+3x^2+7x-2=0 4x^2+7x-2=0 D=b^2-4ac D=49-4*4*(-2)=49+32=81 x1=(-7+9)\8=1\4 x2=(-7-9)\8=-2 x1=1\4 x2=-2